(1) Fear Factor - How much does the movie creep us out? Does it make us want to sleep with the lights on like “The Exoricst?” Does it make our skin crawl like “The Thing?” Does it make us want to to take a shower afterward — or not take a shower if you’re Mr. Hitchcock?

(2) Historical Influence - How many subsequent movies did it inspire? Would there be “The Omen” without “Rosemary’s Baby?” Would there be “The Walking Dead” without “Night of the Living Dead?” Would there be “Saw” without “Se7en?”

(3) Filmmaking Prowess - Does the film make use of masterful cinesthetic techniques? Are there symbolic reflections like Hitchcock’s “Psycho?” Low angles creating a looming apartment like Polanski’s “Repulsion?” Danger lurking just outside the frame like Carpenter’s “Halloween?” Steadicam single-takes through labyrinth mazes like Kubrick’s “The Shining?”

(4) Pop Culture Impact - How engrained is the movie in our collective understanding of Halloween? Can you hum the theme song like “Jaws?” Do you buy the mask for Halloween like “Friday the 13th?” Can you instantly quote it like “Poltergeist?” Do you know the poster tagline like “The Fly” (“Be afraid. Be very afraid”)?

Any one of these four is enough to create horror genre classics. When all four combine, they create movie masterpieces respected by even those who dislike the genre.